You just never feel confident that you've determined the proper line for any putt.
After studying the dynamics of reading greens and how putts break for the better part of three decades, I've developed a simple and uncomplicated method that will help you improve in both areas. Here's how it works:
Step 1: Walk from your ball to a spot behind the hole that's on a direct line between the ball and the cup. From this vantage point, imagine the last three feet of your putt and how the ball will roll as it slows down and curves at perfect speed into the hole.
Step 2: With this last three feet of curve in mind, picture the ball rolling backward to where your putt starts. Connect the two to get the curving track that the ball will roll on once you stroke the putt.
Step 3: Walk back behind your ball and then slide from the ball-hole line [yellow] over to what I call the AimLineâ„¢ of the perfect ball track [green]. Look down the AimLineâ„¢ to see where you must start the putt in order for it to curve into the cup.
Step 4: Move to the ball and "feel" your practice stroke rolling the ball at perfect speed to allow it to break along the perfect ball track. Step in, square your putterface to the AimLine, pull the trigger and... voila.
Why it works
You'd aim a rifle by getting one eye looking directly down the barrel through the sights.You wouldn't aim it from the side.This phenomenon also applies to putting; you can't see the aim direction or imagine the break trajectory if your eyes are positioned away from the starting line of the putt. Aligning your putts with your eyes on the AimLineâ„¢ is the same as looking down the barrel of a rifle. It lets you "see" your stroke target and makes it easy to aim your body, stroke and putt.